1. Field of the Invention
The present invention relates to a fused refractory product having excellent corrosion resistance to iron steel slag.
2. Description of the Prior Arts
Fused refractory products having desired shape and size have been prepared by melting a mixture of sources for refractory having a desired composition by an electric furnace etc. and casting the molten composition in a desired mold and annealing the cast composition under a desired controlled condition to recrystallize it. Sometimes, a furnace which contain a molten mixture of the sources for refractory has been cooled without discharging the molten mixture to recrystallize it.
The fused refractory products have been prepared by such process and have been well-known as high grade refractory products which have substantially different structures from the conventional rebonded refractory products obtained by sintering refractory particles.
The well known cast refractory products include Al.sub.2 O.sub.3 -SiO.sub.2, Al.sub.2 O.sub.3, ZrO.sub.2 -Al.sub.2 O.sub.3 -SiO.sub.2, MgO-Al.sub.2 O.sub.3 -Cr.sub.2 O.sub.3 and Al.sub.2 O.sub.3 -Cr.sub.2 O.sub.3 type refractory products. Among them, the MgO-Al.sub.2 O.sub.3 -Cr.sub.2 O.sub.3 type refractory products have been especially important as a basic refractory product having excellent characteristics superior to the other basic refractory products in the field of industrial production of iron, steel and non-ferrous metals. The refractory products have each stable crystalline structure of periclase and chromespinel phases as main crystals and have excellent corrosion resistance and wearing resistance to various basic slags and have been used for electric furnaces, mixers, vacuum furnace and various smelting furnaces for non-ferrous metals to attain excellent results. A refractory product having superior characteristics has been further required in view of severer conditions in the industrial operation and a development of a superior product has been further required.